[PATCH 01/29] nfsd41: add create session slot buffer to struc nfs4_client

[andros@netapp.com]

From: Andy Adamson <andros@netapp.com>

The nfs41 single slot clientid cache holds create session response which
has a maximum size of 88 bytes. Add a static buffer to struct nfs4_client
to cache the encoded create session response.

Signed-off-by: Andy Adamson <andros@netapp.com>
---
 fs/nfsd/nfs4state.c        |    3 +++
 include/linux/nfsd/state.h |    8 ++++++++
 2 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e82a518..27ad37f 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1283,6 +1283,9 @@ out_new:
 		status = nfserr_resource;
 		goto out;
 	}
+	/* Set the create session cache buffer */
+	new->cl_slot.sl_cache_entry.ce_datav.iov_base = new->cl_slot_buf;
+	new->cl_slot.sl_cache_entry.ce_datav.iov_len = CS_MAX_ENC_SZ;
 
 	copy_verf(new, &verf);
 	copy_cred(&new->cl_cred, &rqstp->rq_cred);
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 14da8f6..87f3eaa 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -174,6 +174,13 @@ struct nfsd4_sessionid {
 #define HEXDIR_LEN     33 /* hex version of 16 byte md5 of cl_name plus '\0' */
 
 /*
+ * maximum encoded size of create session response
+ * 16 - sessionid, 8 - sequence # and flags,
+ * 32 - fore channel attrs, 32 - back channel attrs
+ */
+#define CS_MAX_ENC_SZ  88
+
+/*
  * struct nfs4_client - one per client.  Clientids live here.
  * 	o Each nfs4_client is hashed by clientid.
  *
@@ -206,6 +213,7 @@ struct nfs4_client {
 	/* for nfs41 */
 	struct list_head	cl_sessions;
 	struct nfsd4_slot	cl_slot;	/* create_session slot */
+	char			cl_slot_buf[CS_MAX_ENC_SZ]; /* slot buffer */
 	u32			cl_exchange_flags;
 	struct nfs4_sessionid	cl_sessionid;
 
-- 
1.5.4.3